Fit and finish: Remove border - border is supplied by containing pane.

ILSpy/AnalyzerTreeView.cs

@@ -20,6 +20,7 @@ using System;
 using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Linq;
+using System.Windows;
 using ICSharpCode.ILSpy.TreeNodes.Analyzer;
 using ICSharpCode.TreeView;
 
@@ -48,6 +49,7 @@ namespace ICSharpCode.ILSpy
 		{
 			this.ShowRoot = false;
 			this.Root = new AnalyzerRootNode { Language = MainWindow.Instance.CurrentLanguage };
+			this.BorderThickness = new Thickness(0);
 			ContextMenuProvider.Add(this);
 			MainWindow.Instance.CurrentAssemblyListChanged += MainWindow_Instance_CurrentAssemblyListChanged;
 		}